Problem: $ {5\cdot \left[ \begin{array}{cc} 2 & 4 & -1 \\ 0 & -2 & 1 \end{array} \right]=}$
Explanation: The Strategy To multiply a matrix by a scalar, we multiply each term of the matrix by the scalar. Multiplying each term $ {\begin{aligned}5\cdot \left[\begin{array}{rr} {2} & {4} & {-1} \\ {0} & {-2} & {1} \end{array}\right]&=\left[\begin{array}{rr} 5\cdot{2} & 5\cdot{4} & 5\cdot{-1} \\ 5\cdot{0} & 5\cdot{-2} & 5\cdot{1} \end{array}\right] \\\\&=\left[\begin{array}{rr} {10} & {20} & {-5} \\ {0} & {-10} & {5} \end{array}\right]\end{aligned}}$ Summary $ {5\cdot \left[ \begin{array}{cc} 2 & 4 & -1 \\ 0 & -2 & 1 \end{array} \right]=\left[ \begin{array}{cc} 10 & 20 & -5\\ 0 & -10 & 5 \end{array} \right]}$